The invention relates to a radial piston pump for high-pressure fuel delivery in fuel injection systems of internal combustion engines, in particular in a common rail injection system. A drive shaft that is supported in a pump housing and has an eccentrically embodied shaft segment, on which a ring is slidingly supported that cooperates with preferably a plurality of pistons, which are disposed radially with respect to the drive shaft in a respective cylinder chamber and whose ends oriented toward the drive shaft each have a respective plate.
In this kind of radial piston pump, which is braced on the inside, the plates mounted on the pistons have contact with the ring supported on the drive shaft. Because of the eccentricity of the drive shaft, the pistons are set in succession into a reciprocating motion. The stroke of the pistons is then constant and amounts to twice the eccentricity of the drive shaft.
To improve engine efficiency, it has been proposed that the cylinder chambers be filled with less fuel as the demand drops. In this so-called partial element filling, the components of the radial piston pump are subjected to extreme stress, and both increased wear and damage can occur.